diff -N PhysicalVolumeNavigator.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ PhysicalVolumeNavigator.java	3 Mar 2007 02:24:51 -0000	1.1
@@ -0,0 +1,67 @@

+package org.lcsim.detector;
+
+public class PhysicalVolumeNavigator 
+implements IPhysicalVolumeNavigator
+{
+	private IPhysicalVolume pvTop;
+
+	public PhysicalVolumeNavigator(IPhysicalVolume pvTop)
+	{
+		if ( pvTop == null )
+		{
+			throw new IllegalArgumentException("PhysicalVolumeNavigator cannot be setup with a null PhysicalVolume!");
+		}
+		setTopPhysicalVolume(pvTop);
+	}
+	
+	private String[] splitPath(String path)
+	{
+		// Eat the first slash.
+		if (path.charAt(0) == '/')
+		{
+			path = path.substring(1);
+		}
+		
+		// Split on remaining slashes.
+		return path.split("/");
+	}
+	
+	public IPhysicalVolumePath getPath(String path) 
+	{		
+		String[] names = splitPath(path);
+		IPhysicalVolumePath physvols = new PhysicalVolumePath();
+		IPhysicalVolume pv = getTopPhysicalVolume();
+		for (String name : names)
+		{
+			//System.out.println("looking for physvol = " + name);
+				
+			PhysicalVolumeContainer pvSearch = 
+				pv.getLogicalVolume().getDaughters().findByName(name);			
+			if (pvSearch.size() > 1)
+			{
+				throw new RuntimeException("Got multiple matches on name <"+name+"> in mom <"+pv.getName() + ">.");
+			}
+			else if (pvSearch.size() == 0)
+			{
+				throw new RuntimeException("Path component <"+name+"> was not found!");
+			}
+			else {
+				IPhysicalVolume pvFound = pvSearch.get(0);
+				//System.out.println("found match = " + pvFound.getName());
+				physvols.add(pvFound);
+				pv = pvSearch.get(0);
+			}
+		}
+		return physvols;
+	}
+
+	public IPhysicalVolume getTopPhysicalVolume() 
+	{
+		return pvTop;
+	}
+
+	public void setTopPhysicalVolume(IPhysicalVolume physvol) 
+	{
+		pvTop = physvol;		
+	}
+}

diff -N PhysicalVolumePath.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ PhysicalVolumePath.java	3 Mar 2007 02:24:51 -0000	1.1
@@ -0,0 +1,18 @@

+package org.lcsim.detector;
+
+import java.util.ArrayList;
+
+public class PhysicalVolumePath 
+extends ArrayList<IPhysicalVolume>
+implements IPhysicalVolumePath
+{
+	public String toString()
+	{
+		StringBuffer sb = new StringBuffer();
+		for (IPhysicalVolume physvol : this)
+		{
+			sb.append("/"+physvol.getName());
+		}
+		return sb.toString();
+	}
+}

\ No newline at end of file

diff -u -r1.1 -r1.2
--- DetectorTestUtil.java	3 Mar 2007 01:19:38 -0000	1.1
+++ DetectorTestUtil.java	3 Mar 2007 02:24:51 -0000	1.2
@@ -1,6 +1,8 @@

 package org.lcsim.detector;
 

+import static org.lcsim.units.clhep.SystemOfUnits.cm;

 import static org.lcsim.units.clhep.SystemOfUnits.m;

+import hep.physics.vec.BasicHep3Vector;

 
 import org.lcsim.detector.material.IMaterial;
 import org.lcsim.detector.material.MaterialElement;

@@ -13,12 +15,13 @@

 	public static IPhysicalVolume createTestSetup()
 	{
 		IPhysicalVolume world = createWorld();

-		createBox(world);

+		createTestDetector(world);

 		return world;
 	}
 	

-	public static final void createBox(IPhysicalVolume mom)

+	public static final void createTestDetector(IPhysicalVolume mom)

 	{

+		// Simple box.

 		Box box = new Box("test_box",1.0*m,1.0*m,1.0*m);
 		LogicalVolume lvTest = new LogicalVolume("lvTest",box,dummymat);
 		new PhysicalVolume(

@@ -27,6 +30,17 @@

 				lvTest,
 				mom.getLogicalVolume(),
 				1);

+		
+		// Box daughter volume.
+		Box box2 = new Box("test_box2",10.0*cm,10.0*cm,10.0*cm);
+		LogicalVolume lvTest2 = new LogicalVolume("lvTest2",box2,dummymat);
+		new PhysicalVolume(
+				new CoordinateTransformation3D(
+						new BasicHep3Vector(1.0,0.0,0.0)),
+				"test2",
+				lvTest2,
+				lvTest,
+				1);

 	}
 	
 	public static final IPhysicalVolume createWorld()

diff -u -r1.4 -r1.5
--- ILogicalVolume.java	3 Mar 2007 01:19:38 -0000	1.4
+++ ILogicalVolume.java	3 Mar 2007 02:24:51 -0000	1.5
@@ -21,6 +21,7 @@

 	public ISolid getSolid();
 	public IMaterial getMaterial();
 	public IPhysicalVolumeContainer getDaughters();

+	public int getNumberOfDaughters();

 	public void addDaughter(IPhysicalVolume physvol); 
 	public IPhysicalVolume getDaughter(int i);
 	public boolean isDaughter(IPhysicalVolume physvol);

diff -u -r1.1 -r1.2
--- IPhysicalVolumeNavigator.java	3 Mar 2007 01:19:38 -0000	1.1
+++ IPhysicalVolumeNavigator.java	3 Mar 2007 02:24:51 -0000	1.2
@@ -2,9 +2,10 @@

 
 public interface IPhysicalVolumeNavigator 
 {

+	public IPhysicalVolume getTopPhysicalVolume();

 	public void setTopPhysicalVolume(IPhysicalVolume physvol);

-	public IPhysicalVolumePath getPath(IPhysicalVolume physvol);

 	public IPhysicalVolumePath getPath(String path);

+	//public IPhysicalVolumePath getPath(IPhysicalVolume physvol);

 	//public IPhysicalVolumePath getPath(String[] path);
 	//public IPhysicalVolumePath getPath(int[] copyNums);
 	//public ICoordinateTransformation3D getTransformation(IPhysicalVolume physvol);